Etch system and method for single substrate processing

Abstract

Provided is a method and system for increasing etch rate and etch selectivity of a masking layer on a substrate in an etch treatment system, the etch treatment system configured for single substrate processing. The method comprises obtaining a supply of steam water vapor mixture at elevated pressure, obtaining a supply of treatment liquid for selectively etching the masking layer over the silicon or silicon oxide at a set etch selectivity ratio, placing the substrate into the etch processing chamber, combining the treatment liquid and the steam water vapor mixture, and injecting the combined treatment liquid and the steam water vapor mixture into the etch processing chamber, wherein the flow of the combined treatment liquid and the steam water vapor mixture is controlled to maintain a set etch rate and a set etch selectivity ratio of the masking layer to silicon or silicon oxide.

Description

BACKGROUND[0001]1. Field[0002]The present application generally relates to the design of an etch treatment system and method for increasing etch rate and selectivity of etching a masking layer using a single substrate etch process.[0003]2. Related Art[0004]Current methods in the production of complementary metal oxide semiconductor (CMOS) transistors require masking layers to separate and protect active device regions such as dielectric, metal interconnect, strain, source / drain, and the like. Silicon nitride (Si3N4) or silicon oxide (SiOx, wherein x is greater than 0) is often used as a masking layer due to its electrical and morphological similarity to silicon dioxide (SiO2), as well as because silicon nitride is easily bonded to SiO2. Generally, silicon nitride is used as an etch-stop layer but in certain cases, such as in a “dual damascene” process, the silicon nitride must be etched away without altering the carefully-controlled thickness of the silicon dioxide underlayer. In su...

AI Technical Summary

Benefits of technology

The patent describes a method and system for increasing the rate and selectivity of etching a masking layer on a substrate using a specific treatment liquid and steam water vapor mixture. This method involves combining the treatment liquid and steam water vapor mixture and controlling the flow to maintain a set etch rate and selectivity ratio. The technical effect of this invention is to improve the efficiency and accuracy of etching in a single substrate processing system.

Problems solved by technology

Etch selectivity for ultra-thin layers will become more of a challenge in the future.

Experimental evidence shows that a non-boiling state (i.e., low water content) at elevated temperature does not result in a favorable etch selectivity.

Conversely, to improve selectivity, it would be preferable to have a high concentration of water, (i.e., dilute the acid further), however this is not practical.

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